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Expression and comparison of sweet corn CYP81A9s in relation to nicosulfuron sensitivity
Author(s) -
Choe Eunsoo,
Williams Martin M
Publication year - 2020
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.5848
Subject(s) - sulfonylurea , cytochrome p450 , biology , cleaved amplified polymorphic sequence , amino acid , inbred strain , enzyme , agronomy , horticulture , biochemistry , gene , genotype , microbiology and biotechnology , insulin , restriction fragment length polymorphism
BACKGROUND Nicosulfuron, a sulfonylurea herbicide widely used for grass weed control in corn production, injures some sweet corn hybrids and inbreds. A specific cytochrome P450 (P450), CYP81A9, is suggested to be responsible for sensitivity to nicosulfuron and other P450‐metabolized herbicides. Corn CYP81A9 enzymes were expressed in E. coli and investigated to find the factor(s) associated with their function and variation in metabolizing nicosulfuron. RESULT Recombinant expressed CYP81A9s from tolerant sweet corn inbreds produced an active form of P450, while CYP81A9 from a sensitive inbred produced an inactive form. Nicosulfuron bound to tolerant CYP81A9s, and produced reverse‐type I ligand, while sensitive CYP81A9 showed no interaction with nicosulfuron. Investigation of 106 sweet corn inbreds showed variation in nicosulfuron injury. A survey of sweet corn CYP81A9 sequences showed mutations in codons for amino acids at 269, 284, 375, and 477 occurred in sweet corn inbreds with complete loss of P450 function (with mean injury >91%) and amino acid changes at 208 and 472 occurred in inbreds with moderate and complete loss of P450 function (with mean injury >14%). CONCLUSION Our results support that CYP81A9 enzyme is responsible for metabolizing nicosulfuron in sweet corn, and different types of amino acid changes in CYP81A9 sequence are associated with variation in nicosulfuron injury. Therefore, a careful selection of the tolerant allele will be critical for improving tolerance to nicosulfuron and several other P450‐metabolized herbicides. © 2020 Society of Chemical Industry